The Amp Garage

6.3v for heaters

I have inherited a phaze amplifier that uses a 100VA 300V toroidal power transformer. Its quiet and runs cool. I've been looking at Antek products but their ratings seem different from what typical IE cores are rated. Robrob has a 50va 190volt that he rates at 130 ma. How does he get that figure ?

Dorisant that is the closest thing Ive seen to a silk purse from a sow's ear. I've had that chassis many years ago and came to the conclusion I overpaid for it at $70. From the funky power transformer design with the voltage doubler I didn't understand, to the flimsy sheet metal finger slicing chass...

I had reverb Buzz too. Solved by grounding the tank to the chassis with an alligator clip. I also returned all the reverb grounds to the input jack ground.
Don't use those handy grounding lugs on the RCA jacks !

So then, use a regular noval 9 pin for the PI for less noise and easier packaging without much loss of old amp goodness ?

I just built a one channel 5C8 tweed twin with two 6SL7 preamp tubes and 6L6 / 5U4 as usual. I love it probably because I lucked into a pair of quiet 6SL7s. Question is, if you want the fat round tone of the octal where does it do most of it's tone shaping ? I have 2 octal preamp stages in series an...

Thank you about the tip for grounding the DC heater Aaron. I have discovered that the 0.22 vac leaking from the PS into the second node is getting into my PI output. I tried adding another node previous to my string but that just dropped my voltages too much. I added another 20 mfd cap to the second...

I tried 33 mfd at all 3 nodes with minor improvement. Increasing the 1k resistor value between the nodes and moving the pi down to the third node helped the noise. Just like a tweed amp. Changes the response though..

I hadnt thought of elevating the heaters since I had installed the rectifier for the preamp. Which wasn't very helpful for the noise Im hearing. If I can only have one ground reference, which one is best ? I used to stick the ct on the power tube cathode resistor. That may not work with the ground o...

I tried 3x 33uf ps caps, it helped a little. Increasing the first ps resistor from 1K to 4K7 helped a lot but did not cure it. It also changed the character. I tried a choke but that also didn't help nor did trying different 12AX7 pi tubes. Funny that I just built a tweed 5C8 and a Premier bass amp ...

Well I got the Monarch built and its a fun small amp. I built three of these paraphase amps this year and this one is kicking my butt. No matter what, I cant get rid of the severe hum. Seems to be tied to the PI. It goes up and down with the 10K pot and is lowest at the pots lowest setting. At this ...

Best tool on the world. Catty Man parabolic cat claw trimmers. Work esp well on teflon wire. They look like small stubby nail scissors with a parabolic blade.

I decided to try one of these too. Just for fun. I tore up an old Z-28 clone made of Hammond organ parts and we are in process.

Thank you Maker dp. Merlin's board is roughly what I was looking for. Now if they were only in stock.

I should have specified for a 20 to 50 watt guitar tube amp. I imagine someone has designed one and had to meet the minimum order for pcb production . So what is that like 100 units ?